【摘要】 采用MP406水分传感器、WM-1负压计和DT80数据记录仪等设备,开发了一套毛细上升试验系统,对非饱和含黏土砂做了3个不同初始含水率的毛细上升试验,得到了试样各个断面的含水率和吸力随时间的变化规律。研究表明:初始含水率对毛细上升高度和上升速度有显著影响,本套系统可测定毛细上升的实际高度,在土样渗透系数未知的情况下可对不同土样测定其毛细上升的最大高度;可根据湿润锋运动速度、土样含水率变化和吸力变化数值,确定非饱和土渗水系数,从而避免了渗透系数确定费时、费力的困难;可由吸力预测试样的渗水系数,只需测定该土的土-水特征曲线或进行吸力量测即可确定出该土在这一吸力下的渗水系数;并拟合出不同初始含水率试样的湿润锋随时间变化规律。更多还原

【Abstract】 A set of test system for studying capillary rise has been developed by using MP406 moisture probe,WM-1 suction probe and DT80 logger,etc.The system has been used to carry out 3 poles of different initial water contents capillary rise tests on unsaturated clayey sand with controlled 1.7 g/cm3 dry density.The relationships between different cross-sections water contents and suctions and time are obtained.The results indicate that the initial water content has a great effect on capillary rise hight and rising velocity.This system could measure wetting front advancing velocity at different time and study changing water content and suction of different cross-sections.This system could fix quantity study capillary rising maximum hight and unsaturated hydraulic conductivity to resolve the difficulties that using general methods couldn’t measure.It can measure unsaturated hydraulic conductivity according to wetting front advancing velocity,water content changing & suction changing of samples.Coefficient of permeability will be get from soil water characteristic curve.At the same time,the laws of wetting front movement are given under different initial water contents.更多还原